Protecting and cooling means for dynamo-electric machines



March 3, 1931. w, $|LER 1,794,649

PI KOTECTING AND COOLING MEANS FOR DYNAMO ELECTRIC MACHINES Filed Jan.51, 1929 V M /g a0 1 la INVENTOR ATTbRNEY Patented Mar. 3, 1931 UNITEDSTATES PATENT OFFICE ALFRED W. SILER, OF INDIANAPOLIS, INDIANA,.ASSIGNOR TO FAIRBANKS, MORSE & 00., OF CHICAGO, ILLINOIS, A CORPORATIONOF ILLINOIS PROTECTING AND COOLING MEANS FOR DYNAhIO-ELECTRIC MACHINESApplication filed January 31, 1929. Serial No. 336,345.

This invention relates to improvements in protecting and cooling meansfor dynamoelectric machines, and particularly to combined ventilating,cooling and protecting apparatus for electric motors.

An object of the present invention is to provide improved means forreadily and eas ily converting an open type motor into a motor ofenclosed type, without impairing the existing rating and efiiciency ofthe motor.

A further object is to provide an enclosing apparatus of improved formand construction, which will serve not only as an agitator to cause acurrent of cooling air to be passed over the conducting parts of anelectric motor, but will also serve as a means for effectivel andentirely preventing the entrance of dirt or foreign matter to the liveparts of the machine.

Further, objects and advantages of the present invention will appearfrom the following detailed description of parts, and the accompanyingdrawing which shows a vertical sectional elevation of one end of anelectric motor to which the improvements have been applied.

The older prevailing devices provided for ventilation of electricmotors, or the like, by means of elaborately andexpensively con structedfans and impellers with related air channels, either internally orexternally of the motor frame. Vhile such devices are no doubteffective, within limits, they add materially to the cost of themachine, and the parts of the machine must usually be designed oraltered particularly for the reception of these devices. To the end ofobviating the expense and space requirement of such apparatus, it is afurther purpose and object to provide an efiicient cooling andprotecting means which may be attached to an electric motor of the opentype, either at the time of manufacture, or be supplied as an accessory,to be attached and installed by a motor user, with a minimuminterruption of service.

Further, the older prevailing devices usually employ a plurality ofparts, some or all or which are difiicult and expensive to mainiiacture,and which in some cases are characterized which uctivity and which ischar- 1 ides 4 acteriacd by c contour, which elimi the pc* liliy of dirtlodging on arts may be forn'ied of copper t metal or certain alloysmetals having the requisite h It c nductivity.

It w If course, be understood that the sent uetaiied description and theaccom- 7 ing, relate to a single prenai embodiment of the presn, andthat substantial changes 3c in do in the described construction of partswithout departing from the spirit and scope oi he invention.

Refs by numerals to the drawings, 10 designates, ens-rally, an electricmotor which may be of any conventional construction. The motor 10 isprovided with a stator 11, and core 12 in which is provided statorwindings 13. The stator 11 comprises a part of, or is carried by andwithin the usual frame of the machine, having, in the present example,end members 14 provided with hearing arms 15 in which are fitted themotor bearings for motor shaft 16. The rotor 17 is in rigid connectionwith the shaft and comprises 3y preference, a laminated core portion 18which is slotted in the usual manner to receive the rotor bars, notshown, each of which is secured to an end ring 19. its particularlypertinent to the present improvements to be descri ed hereinafter, itwill be noted that windings 13 have a lateral extending coil portion 20.

Cooling of the windings and live parts of the machine effected byintroducing air through openings 21 form d in the end member 14, whichair may be circulated in one end of the motor and out the opposite endthereof, or in some cases may be introduced intermediately of the frameand expelled from both ends of the motor, as is usual in s itself toform a substa nd protecting vrably of cast on is extend radial fan eleare provided. on opposit sides or a Wall portion .ill be seen that themember 2 is so posi l along the shaft 16, to fo ii an air channel orspace between the member 2e and the rotor of the machine. Beyond the fanelements 26 a l and int the member 2 ab.

slot- 29, i shield or shroud Z31 at. The shield 31 1s prei 7L 1 3 iormeoOi at conduc he shield cooling "member 31 e tlvity. i is eaten ded L.Z'WZIJ" iv the member 2%, and

and outwardly from s, cupped portion ly U shaped secof arcuate orsuastan tion, which, as will be seen rrom the drawing,

serves to enclose the coil ndings. The outermost portion or edge tlislield overlaps outwardly extendn v tionary portion 3a of the frame such ashoe 35, and is fixedly secured thereto. fhe cooling member 31 isof'suilicient rigidity to retain its initial'conformity. but it is stillof suffi at flexibility to enable :ne edge portion 20 of the to bedisplaced sufficiently to form a reasonably close, running; fit with theadg'acen portions of the slot 29, and thereby forms a run ning sealbetween elements 24- and 31. This provision prevents the entrance ofdirt or foreignmatter to the live parts of the machine, from the surounding atmosphere.

While for convenience of illustration I have shown only one end of amotor equipped according to this invention, it will be under stood thatthe opposite end is, by great preference, similarly equipped with theelements 31 and 24. it is thus seen that a motor provided with thepresent improvements, is effece tively divided into separate aircirculating chambers, and that each of such chambers is pocketed orshielded against circulation and intermingling with the air of the otherthereof. The ob *ious efiect of the rotation of the fan carrying member24, will be to insure a complete agitation and circulation of the airagainst the opposite sides of the shields 31. The enclosed air'is cooledby radiation and convection, through the relatively thin sheet metal ofthe shield and by the circulationset up by the fan element 27. The heatabsorbed turned inwardly upon said shield.

by the shield 31 is dissipated by the exterior cooling air stream fromeach of the fans 26. The air is directed to the fan element 26, fromthe, openings 21, by the guide element 22, Which also directs an aircurrent from the against the outer surface of the shield. The describedforce-d circulation of air around the interior and exterior spacesdefined by the shield 31 and member 24, Will serve effectively to coolall lieatin portions of the machine upon operation thereof at anysubstantial speed.

. use, the device described has been found to he applicable to motors ofexisting standard construction. and motors equipped in the mannerdescribed are at least the full equivalent, so far performance andcharacteristics are concerned, of the open type motor, With the addedfeature of protection of the live parts of the motor from dirt orforeign matter from the surrounding air.

I claim as my invention: p 7

A motor including a motor shaft, a rotor thereon, a stator, statorwindings and end ers, a combined cooling and protecting vice includingan annular stator shield g horizontally and inwardly not-or, the outeredge being secured to .onary portion of the machine for fixed 1 mt ofthe shield; a cast sealing ringremovably mounted on the motor shaft, in,spaced relation to the rotor, and having a slot adapted to receive andform'a running fit With the inner edge of tne shield, combined radiatingand fan blades formed integrally With, and on opposite sides of thesealing ring, and a halile' formed of sheet metal, removably mounted onan end member of the machine, and adapted to deflect a current ofcooling air against the outside surface of ALFRED W. SILER.

